1. Technical Field
Aspects of the invention relate to an image formation apparatus such as a color laser printer.
2. Related Art
Typically, in the color laser printer, a plurality of photoconductive drums corresponding to colors of yellow, magenta and cyan are arranged. Further, in association with respective photoconductive drums, a plurality of developing units, which supply toner to respective photoconductive drums to form toner images, are provided.
When a color image is formed, each of the developing units is driven and a toner image is formed on each of the photoconductive drums. The toner images formed on respective photoconductive drums are transferred onto a printing sheet, directly or indirectly (e.g., via an intermediate transfer belt), a plurality of color toner images are overlaid and a color image is formed on the printing sheet.
When a monochrome image is formed, it is only necessary that a black toner image is formed on a photoconductive drum for forming a black image, which is transferred onto a printing sheet, directly or indirectly. Therefore, in such a case, it is only necessary to drive a developing unit for forming a black image, and it is not necessary to drive the developing units for forming yellow, magenta or cyan image.